Hamas militants say they have arrested about 50 members of the rival Fatah political faction in the Gaza Strip. The arrests came one day after seven people were killed in violence between the two factions. VOA's Jim Teeple reports from Jerusalem.

Monday's violence was the worst since Hamas seized control of the Gaza Strip from Fatah in June.

Hamas gunmen reportedly opened fire at a mass demonstration called to commemorate the third anniversary of the death of Palestinian President Yasser Arafat. In the ensuing violence, Hamas and Fatah gunmen exchanged fire, causing scenes of chaos reminiscent of the worst fighting between the two factions earlier this year.

On Tuesday, Hamas militants arrested Fatah supporters in Gaza they claim were responsible for some of the violence at the rally, which was attended by an estimated 200,000 people. Yasser Abd Rabo, a senior Fatah official and a close aide to moderate Palestinian President Mahmoud Abbas, accused Hamas of criminal behavior.

Rabo says Hamas militants in Gaza are isolating themselves from ordinary Palestinians and behaving like the Israeli occupation forces.

President Abbas, whose Fatah-led government controls the West Bank, declared three days of mourning in the Palestinian territories. Most businesses were closed in Gaza City Tuesday.

Mohammed Dahlan, the senior Fatah leader in Gaza until he was forced to leave the territory in June, has called for more rallies to protest Hamas in Gaza, saying ordinary Palestinians have had enough of Hamas rule.